Method and apparatus for irradiation treatment of elongate materials

Claim 2

In the method for irradiating an elongate cylindrical target with a linear beam source of electrons comprising the steps of inducing said electron beam to divert from its path at a predetermined point thereon, establishing a constant magnetic field aligned with the initial path of said electron beam in the region into which said diverted electron beam is diverted so that said electrons follow helical paths converging at a point on said initial electron beam path 360 helical degrees away from the point of diversion, passing said elongate target through said point of conversion at a small angle to the initial axis of said linear electron beam whereby said electrons impinge into said target at an oblique angle corresponding substantially to the pitch angle of said helix, said electron beam thereby entering the surface of said elongate target material at an oblique angle, and causing the direction of diversion of said electron beam to rotate about said axis.

Claim 3

In the method for irradiating an elongate cylindrical target with a linear beam source of electrons comprising the steps of inducing said electron beam to divert from its path at a predetermined point thereon, establishing a constant magnetic field aligned with the initial path of said electron beam in the region into which said diverted electron beam is diverted so that said electrons follow helical paths converging at a point on said initial electron beam path 360 helical degrees away from the point of diversion, passing said elongate target through said point of conversion at a small angle to the initial axis of said linear electron beam whereby said electrons impinge into said target at an oblique angle corresponding substantially to the pitch angle of said helix, said electron beam thereby entering the surface of said elongate target material at an oblique angle, and causing the direction of diversion of said electron beam to rotate about said axis.

Claim 4

In the method for irradiating an elongate cylindrical target with a linear beam source of electrons comprising the steps of inducing said electron beam to divert from its path at a predetermined point thereon, establishing a constant magnetic field aligned with the initial path of said electron beam in the region into which said diverted electron beam is diverted so that said electrons follow helical paths converging at a point on said initial electron beam path 360 helical degrees away from the point of diversion, passing said elongate target through said point of conversion at a small angle to the initial axis of said linear electron beam whereby said electrons impinge into said target at an oblique angle corresponding substantially to the pitch angle of said helix, said electron beam thereby entering the surface of said elongate target material at an oblique angle, and causing the direction of diversion of said electron beam to rotate about said axis.

Claim 5

In a method for irradiating a cylindrical object through a surface thereof within an electron beam, the steps of bending said electron beam along a helical path having a length of 360 helical degrees, said path beginning and ending on the initial axis defined by said electron beam, rotating the helically bent beam about the initial axis to thereby intersect said axis at an oblique angle and sweep a cone-shaped path thereabout having an apex at a point on said axis and making an angle thereto lying in the range from about 10 to 80*, delivering an object to be irradiated through said cone-shaped path at said apex so that said beam intersects that object at an oblique angle determined substantially by the pitch of said helix and at said oblique angle, said beam being effective thereby to irradiate portions of said object at or near the surface thereof and in a region immediately adjacent to the position of entry of said beam into said object together with deeper portions of said object which are spaced from said surface.

Claim 6

In a method for irradiating a cylindrical object through a surface thereof within an electron beam, the steps of bending said electron beam along a helical path having a length of 360 helical degrees, said path beginning and ending on the initial axis defined by said electron beam, rotating the helically bent beam about the initial axis to thereby intersect said axis at an oblique angle and sweep a cone-shaped path thereabout having an apex at a point on said axis and making an angle thereto lying in the range from about 10 to 80*, delivering an object to be irradiated through said cone-shaped path at said apex so that said beam intersects that object at an oblique angle determined substantially by the pitch of said helix and at said oblique angle, said beam being effective thereby to irradiate portions of said object at or near the surface thereof and in a region immediately adjacent to the position of entry of said beam into said object together with deeper portions of said object which are spaced from said surface.

Claim 7

In apparatus for irradiating an elongate object with an electron beam, means forming a linear stream of electrons travelling along a predetermined axis, an irradiation chamber having an input for receiving said electron stream, means for maintaining a reduced pressure within said chamber, means located at said input for divertiNg said electron stream from said axis, said means including a magnetic ring for generating a magnetic field directed transversely to said stream and rotating about said stream at a uniform speed, means associated with said chamber for feeding said elongate object therethrough while permitting said partial pressure to be maintained in said chamber, a solenoid magnet surrounding said chamber to establish a uniform magnetic field within said chamber and oriented in alignment with the direction of said electron beam axis for causing said diverted electron stream to follow a helical path having a focal point 360 helical degrees along the axis, said means for feeding said elongate object being arranged to cause said object to intersect said focal point at less than a small angle to said axis.

Claim 8

In apparatus for irradiating an elongate object with an electron beam, means forming a linear stream of electrons travelling along a predetermined axis, an irradiation chamber having an input for receiving said electron stream, means for maintaining a reduced pressure within said chamber, means located at said input for divertiNg said electron stream from said axis, said means including a magnetic ring for generating a magnetic field directed transversely to said stream and rotating about said stream at a uniform speed, means associated with said chamber for feeding said elongate object therethrough while permitting said partial pressure to be maintained in said chamber, a solenoid magnet surrounding said chamber to establish a uniform magnetic field within said chamber and oriented in alignment with the direction of said electron beam axis for causing said diverted electron stream to follow a helical path having a focal point 360 helical degrees along the axis, said means for feeding said elongate object being arranged to cause said object to intersect said focal point at less than a small angle to said axis.

Claim 9

Apparatus for irradiating an elongate cylindrical target with a linear beam source of electrons comprising means for inducing said electrons to divert from the path of said beam from a predetermined point thereon, magnetic means for establishing a constant magnetic field aligned with the initial electron path in the region into which said diverted electron beams are directed so that said electrons follow helical paths therein converging at a point on said path 360 helical degrees away from said point of diversion, means for passing said elongate target through said point of convergence at a small angle to the initial axis of said electron beam whereby said electrons impinge into said target at an oblique angle corresponding generally to the pitch angle of said helix, said electron beam thereby entering the surface of said elongate target material at an oblique angle, and means for causing the direction of diversion of said beam to rotate about said axis.

Claim 10

Apparatus for irradiating an elongate cylindrical target with a linear beam source of electrons comprising means for inducing said electrons to divert from the path of said beam from a predetermined point thereon, magnetic means for establishing a constant magnetic field aligned with the initial electron path in the region into which said diverted electron beams are directed so that said electrons follow helical paths therein converging at a point on said path 360 helical degrees away from said point of diversion, means for passing said elongate target through said point of convergence at a small angle to the initial axis of said electron beam whereby said electrons impinge into said target at an oblique angle corresponding generally to the pitch angle of said helix, said electron beam thereby entering the surface of said elongate target material at an oblique angle, and means for causing the direction of diversion of said beam to rotate about said axis.

Claim 11

Apparatus as in claim 4 further including beam position detectors located on each side of the target position, means for sensing the output of said detectors and for using the same to control the means for diverting said beam so that change of position of said convergence point causes corresponding change in the strength of said diverting field to thereby stabilize the position of said beam on said target.